JPH1045634A - Production of low polymeric alpha-olefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to continuously obtain the subject compound in high yield and selectivity without generating a polymer as a by-product by feeding each component of a chromium-based compound catalyst in a specific rate to a reaction zone at the beginning of a reaction to initiate the reaction of an α- olefin. SOLUTION: In continuously reacting (B) α-olefin to polymerize into a low polymer using (A) a chromium-based catalyst consisting of a chromium compound (A1 ), a nitrogen-containing compound (A2 ) which is an amine, an amide or an imide and an alkylaluminum compound (A3 ), each component of the component A and the component B are fed to a reaction zone so that each of molar ratios A2 /A1 and A3 /A1 is made higher than the molar ratio in a stationary state to initiate the low polymerization reaction of the component B. It is preferable to feed each component of the component A and the component B to the reaction zone while keeping A1 and A3 apart not to come into contact with each other, thus, the objective compound can be obtained in high purity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an α-olefin low polymer, and more particularly to a method for producing an α-olefin low polymer mainly composed of 1-hexene from ethylene in a high yield. The present invention relates to an industrially advantageous method for producing an α-olefin low polymer which can be produced at a high selectivity.

[0002]

2. Description of the Related Art Heretofore, as a method for low polymerization of an α-olefin such as ethylene, a method using a chromium catalyst comprising a combination of a specific chromium compound and a specific organic aluminum compound has been known. For example,
No. 18707 describes a method for obtaining 1-hexene from ethylene using a catalyst system comprising a transition metal compound of the VIA group containing chromium and polyhydrocarbyl aluminum oxide.

JP-A-3-128904 discloses that an α-olefin is trimerized by using a catalyst obtained by previously reacting a chromium compound having a chromium-pyrrolyl bond with a metal alkyl or Lewis acid. A method is described. Also, JP-A-6-239920 discloses that
A method for low polymerization of an α-olefin using a catalyst obtained by mixing a chromium compound, a pyrrole, a metal alkyl compound and a halide source in a common solvent is described. Further, JP-A-8-3216 discloses that at least a chromium catalyst comprising an chromium compound, an amine or metal amide, an alkylaluminum compound and a halogen compound is used, and the α-olefin and the chromium catalyst are in a specific contact mode. And low polymerization of α-olefins.

[0004]

However, any of the above methods cannot avoid by-products of a considerable amount of polymer. Polymer by-products cause problems such as adhesion of polymers to equipment and removal of polymers from reaction product liquids. This is an important issue when implementing it. The present invention has been made in view of the above circumstances, and an object of the present invention is to use a chromium-based catalyst to reduce the production of α-olefin low polymers such as 1-hexene and the like while suppressing the by-product of the polymer, and attaining a high yield. And to provide a method for producing an α-olefin low polymer which can be produced at a high selectivity, and particularly, using a chromium-based catalyst, without involving an induction period for activating the catalyst at the beginning of the reaction, An object of the present invention is to provide a method for producing an α-olefin low polymer in an industrially advantageous manner while being active and suppressing the by-product of the polymer.

[0005]

That is, the gist of the present invention is as follows.
The α-olefin is subjected to low polymerization reaction using a chromium-based catalyst comprising at least a combination of a nitrogen-containing compound (b) and an alkylaluminum compound (c) selected from the group consisting of a chromium compound (a), an amine, an amide and an imide. In the method for continuously producing an α-olefin low polymer, the molar ratio of the nitrogen-containing compound (b) / chromium compound (a) and the alkylaluminum compound (c) / chromium in the reaction zone at the start of the reaction The components of the chromium-based catalyst and the α-olefin are supplied so as to start the low polymerization reaction of the α-olefin so that the molar ratio of the compound (a) becomes larger than the molar ratio in the steady state. a method for producing an α-olefin low polymer.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, a catalyst system comprising at least a combination of a chromium compound (a), a nitrogen-containing compound (b) and an alkylaluminum compound (c) is used as the chromium-based catalyst. As a preferred embodiment, a catalyst system comprising a combination of a chromium compound (a), a nitrogen-containing compound (b), an alkylaluminum compound (c) and a halogen-containing compound (d) is used.

The chromium compound (a) used in the present invention is
It is represented by the general formula CrXn. However, in the general formula, X is
Any organic or inorganic group or negative atom, n is 1 to
And represents an integer of 6, and when n is 2 or more, Xs may be the same or different from each other. The valence of chromium is 0
It is hexavalent, and n in the above formula is preferably 2 or more.

The organic group usually has 1 to 30 carbon atoms.
Of various groups. Specific examples include a hydrocarbon group, a carbonyl group, an alkoxy group, a carboxyl group, a β-diketonate group, a β-ketocarboxyl group, a β-ketoester group, and an amide group. Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an aryl group, an alkylaryl group, an aralkyl group, and a cyclopentadienyl group. Examples of the inorganic group include a chromium salt-forming group such as a nitrate group and a sulfate group, and examples of the negative atom include oxygen and halogen.

Preferred chromium compounds are chromium alkoxy salts, carboxyl salts, β-diketonate salts, salts of β-ketoesters with anions, or chromium halides, specifically chromium (IV) -t- Butoxide, chromium (III) acetylacetonate, chromium (III)
Trifluoroacetylacetonate, chromium (III) hexafluoroacetylacetonate, chromium (III) (2,
2,6,6-tetramethyl-3,5-heptanedionate), Cr (PhCOCHCOPh) ₃ (where Ph represents a phenyl group), chromium (II) acetate, chromium (III) acetate, chromium (III) -2-ethylhexanoate, chromium (III) benzoate, chromium (III) naphthenate, Cr (CH ₃ COCHCOOCH
₃ ) ₃ , chromium chloride, chromium chloride, chromium bromide, chromium bromide, chromium iodide, chromium iodide, chromium fluoride, chromium fluoride, etc. Is mentioned. Further, a complex comprising the above chromium compound and an electron donor can also be suitably used. Examples of the electron donor include compounds containing nitrogen, oxygen, phosphorus or sulfur.

As the nitrogen-containing compound, nitrile,
Examples include amines and amides, and specific examples include acetonitrile, pyridine, dimethylpyridine, dimethylformamide, N-methylformamide, aniline, nitrobenzene, tetramethylethylenediamine, diethylamine, isopropylamine, hexamethyldisilazane, and pyrrolidone. Can be

As the oxygen-containing compound, esters,
Ether, ketone, alcohol, aldehyde, etc., and specific examples thereof include ethyl acetate, methyl acetate, tetrahydrofuran, dioxane, diethyl ether, dimethoxyethane, diglyme, triglyme, acetone, methyl ethyl ketone, methanol, ethanol, acetaldehyde and the like. .

Examples of the phosphorus-containing compound include hexamethylphosphoramide, hexamethylphosphorustriamide, triethylphosphite, tributylphosphine oxide, and triethylphosphine. Examples of the sulfur-containing compound include carbon disulfide, dimethyl sulfoxide, tetramethylene sulfone, thiophene, and dimethyl sulfide.

Therefore, the chromium compound and the electron donor
Complexes such as chromium halide ether complexes
Body, ester complex, ketone complex, aldehyde complex,
Cole complex, amine complex, nitrile complex, phosphine complex
And thioether complexes. In particular,
CrCl_Three・ 3THF, CrCl_Three・ 3DOX, CrC
l_Three・ (CH_ThreeCO_Two-N-C_FourH₉), CrCl_Three・
(CH_ThreeCO_TwoC_TwoH _Five), CrCl_Three・ 3 (i-C_Three
H₇OH), CrCl_Three.3 [CH_Three(CH_Two)_ThreeCH
(C_TwoH_Five) CH_TwoOH], CrCl_Three・ 3PRD, C
rCl_Three・ 2 (i-C_ThreeH₇NH_Two), [CrCl_Three・
3CH_ThreeCN] ・ CH_ThreeCN, CrCl _Three・ 3PP
h_Three, CrCl_Two・ 2THF, CrCl_Two・ 2PRD,
CrCl_Two・ 2 [(C_TwoH_Five)_TwoNH], CrCl_Two・
2CH_ThreeCN, CrCl_Two.2 [P (CH_Three)_TwoPh]
(Where DOX is dioxane, PRD
Represents pyridine, respectively).

As the chromium compound, a compound soluble in a hydrocarbon solvent is preferable, and β-diketonate salt of chromium;
Carboxylates, salts of β-ketoesters with anions, β
-Ketocarboxylates, amide complexes, carbonyl complexes, carbene complexes, various cyclopentadienyl complexes, alkyl complexes, phenyl complexes and the like. Specific examples of various chromium carbonyl complexes, carbene complexes, cyclopentadienyl complexes, alkyl complexes and phenyl complexes include C
r (CO) ₆ , (C ₆ H ₆ ) Cr (CO) ₃ , (CO)
₅ Cr (= CCH ₃ (OCH ₃ )), (CO) ₅ Cr
(= CC ₆ H ₅ (OCH ₃ )), CpCrCl ₂ (where Cp represents a cyclopentadienyl group), (Cp * C
rClCH ₃ ) ₂ (where Cp * indicates a pentamethylcyclopentadienyl group), (CH ₃ ) ₂ CrCl and the like.

The chromium compound can be used by being supported on a carrier such as an inorganic oxide. However, it is preferable to use the chromium compound in combination with other catalyst components without supporting the carrier. That is, in the present invention, the chromium-based catalyst is preferably used in a specific contact mode described later, and according to such a mode, a high catalytic activity can be obtained without carrying the chromium compound on a carrier. In the case where the chromium compound is used without being supported on the carrier, it is not necessary to carry the chromium compound on the carrier with complicated operations, and the use of the carrier increases the total amount of the catalyst used (the total amount of the carrier and the catalyst component). Can be avoided.

The nitrogen-containing compound (b) used in the present invention is
One or more compounds selected from the group consisting of amines, amides and imides. The amine used in the present invention is a primary or secondary amine. Primary amines include ethylamine, isopropylamine, cyclohexylamine,
Benzylamine, aniline, naphthylamine and the like are exemplified, and as the secondary amine, diethylamine, diisopropylamine, dicyclohexylamine, dibenzylamine, bis (trimethylsilyl) amine, morpholine, imidazole, indoline, indole, pyrrole, 2,
5-dimethylpyrrole, 3,4-dimethylpyrrole,
Examples thereof include 3,4-dichloropyrrole, 2,3,4,5-tetrachloropyrrole, 2-acetylpyrrole, pyrazole, and pyrrolidine.

The amide used in the present invention includes 1
Metal amides derived from primary or secondary amines, such as primary and secondary amines described above with IA
Amides obtained by reaction with a metal selected from Group IIA, Group IIA, Group IIIB and Group IVB. Specific examples of such a metal amide include lithium amide, sodium ethylamide, calcium diethylamide, lithium diisopropylamide, potassium benzylamide, sodium bis (trimethylsilyl) amide, lithium indolide, sodium pyrrolide, lithium pyrrolide, and potassium pyrrolide. , Potassium pyrrolidide, aluminum diethylpyrrolidide, ethylaluminum dipyrrolide, aluminum tripyrolide and the like.

In the present invention, the above-mentioned secondary amine, 2
Metal amides derived from secondary amines or mixtures thereof are preferably used. In particular, as the secondary amine, pyrrole, 2,5-dimethylpyrrole, 3,4-dimethylpyrrole, 3,4-dichloropyrrole, 2,3,4,5
Metal amides derived from tetrachloropyrrole, 2-acetylpyrrole and secondary amines include aluminum pyrrolide, ethylaluminum dipyrrolide, aluminum tripyrolide, sodium pyrrolide, lithium pyrrolide, and potassium pyrrolide Is preferred. And
Among pyrrole derivatives, derivatives having a hydrocarbon group on the pyrrole ring are particularly preferred. The amide or imide compound other than the above used in the present invention includes the following general formula (1)
To (3).

[0019]

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In the general formula (1), M ¹ is a hydrogen atom or a metal element selected from Groups IA, IIA and IIIB of the periodic table, and R ¹ is a hydrogen atom, an alkyl having 1 to 30 carbon atoms. Group, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, or an aryl group which may contain a hetero element, wherein R ² is a hydrogen atom,
30, an alkyl group, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, an aryl group which may contain a hetero element, or an acyl group C (＝ O) R
³ (the definition of R ³ is the same as R ^1, may be different from R ¹⁾ represents may be bonded to each other to form a ring R ¹ and R ^2.

In the general formula (2), M ² and M ³ are a hydrogen atom or a metal element selected from Groups IA, IIA and IIIB of the periodic table, and R ⁴ and R ⁵ are a hydrogen atom, a carbon atom Number 1
Represents an alkyl group, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, or an aryl group which may contain a hetero element, wherein R ⁴ and R ⁵ form a ring; A may represent an alkylene group which may contain an unsaturated bond.

In the general formula (3), M ⁴ is a hydrogen atom or a metal element selected from Groups IA, IIA and IIIB of the periodic table, and R ⁶ is a hydrogen atom, an alkyl having 1 to 30 carbon atoms. Group, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, or an aryl group which may contain a hetero element, wherein R ⁷ is a hydrogen atom,
30, an alkyl group, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, an aryl group which may contain a hetero element, or a SO ₂ R ⁸ group (R ⁸ is defined as R ⁶ The same and may be different from R ⁶ )
And R ⁶ and R ⁷ may combine with each other to form a ring.

Examples of the amide represented by the general formula (1) or (2) include, for example, acetamide, N-methylhexaneamide, succinamide, maleamide, N-methylbenzamide, imidazole-2-carboxamide, di-amide. 2-thenoylamine, β-lactam, δ-lactam, ε-caprolactam, and salts thereof with metals of Groups IA, IIA or IIIB of the Periodic Table;
Examples of the imides include 1,2-cyclohexanedicarboximide, succinimide, phthalimide, maleimide, 2,4,6-piperidinetrione, perhydroazecin-2,10-dione, and these compounds and those in the periodic table. Salts with metals of groups IA, IIA or IIIB.

The sulfonamides and sulfonimides represented by the general formula (3) include, for example, benzenesulfonamide, N-methylmethanesulfonamide, N-
Methyl trifluoromethanesulfonamide, and salts thereof with metals of Groups IA, IIA or IIIB of the Periodic Table. Among these amide or imide compounds, compounds represented by the general formula (1) are preferable, and particularly,
An imide compound in which R ² in the general formula (1) represents an acyl group C (＝ O) R ³ and R ¹ and R ² form a ring is preferable. In the present invention, as the alkylaluminum compound (c), an alkylaluminum compound represented by the following general formula (4) is suitably used.

[0025]

## STR2 ## _{^{R 1 m Al (OR 2)}} n H p X q ... (4)

In the general formula (4), R ¹ and R ² are hydrocarbon groups having usually 1 to 15, preferably 1 to 8 carbon atoms, which may be the same or different, and Represents a halogen atom, m, n, p and q are each 0 <m
≤3, 0≤n <3, 0≤p <3, and 0≤q <3, and represent a number that satisfies m + n + p + q = 3.

Examples of the alkylaluminum compound include a trialkylaluminum compound represented by the following general formula (5), an alkylaluminum halide compound represented by the following general formula (6), and an alkoxyaluminum compound represented by the following general formula (7) Compounds, alkylaluminum hydride compounds represented by the general formula (8), and the like. The meanings of R ¹ , X and R ² in each formula are the same as described above.

[0028]

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Specific examples of the above alkylaluminum compound include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, diethylaluminum ethoxide, diethylaluminum hydride and the like. Of these, trialkylaluminum is particularly preferred in that it produces less polymer by-products. The alkylaluminum compound may be a mixture of two or more.

In the present invention, the catalyst is (a)
Essentially formed from the three components (b) and (c),
It is preferable to use a halogen-containing compound (d) in addition to these three components. The halogen-containing compound (d) is not limited as long as it is a compound containing a halogen atom, but the following halogen-containing compounds (1) to (4) are preferable.

The halogen-containing compound (1) is a compound of the periodic table
It is a halogen-containing compound containing an element selected from Group IIIA, IIIB, IVA, IVB, VA, VB and VIB. Specifically, scandium chloride, yttrium chloride, lanthanum chloride, titanium tetrachloride, zirconium tetrachloride, hafnium tetrachloride, boron trichloride, aluminum chloride, diethyl aluminum chloride, ethyl aluminum sesquichloride, gallium chloride, carbon tetrachloride, chloroform , Methylene chloride, dichloroethane, hexachlorobenzene,
1,3,5-trichlorobenzene, trityl chloride,
Silane tetrachloride, trimethylchlorosilane, germanium tetrachloride, tin tetrachloride, tributyltin chloride, phosphorus trichloride, antimony trichloride, trityl hexachloroantimonate, antimony pentachloride, bismuth trichloride, boron tribromide, aluminum tribromide, tetra Examples thereof include carbon bromide, bromoform, bromobenzene, iodomethane, silicon tetrabromide, hexafluorobenzene, and aluminum fluoride. Among these, a compound having a large number of halogen atoms is preferable, and a compound soluble in a solvent for performing a low polymerization reaction is preferable. As the halogen of the halogen-containing compound (1), it is preferable to use bromine or chlorine, especially chlorine in view of the activity, selectivity of the target product, and the like. Particularly preferable halogen-containing compound (1) is carbon tetrachloride, Chloroform, dichloroethane, titanium tetrachloride, germanium tetrachloride, tin tetrachloride. A mixture of two or more of these can also be used.

Next, the halogen-containing compound (2) is a straight-chain hydrocarbon having 2 or more carbon atoms substituted with 3 or more halogen atoms. The straight-chain hydrocarbon in the halogen-containing compound (2) is preferably a straight-chain saturated hydrocarbon. A straight-chain hydrocarbon in which two or more adjacent carbon atoms are substituted with three or more halogen atoms is preferable, and a straight-chain halogenated carbon represented by the following general formulas (9), (10) and (11). Hydrogen is particularly preferred.

[0033]

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In the general formula (9), X ^{1 to} X ⁸ represent a hydrogen atom or a halogen atom, at least three of X ^{1 to} X ⁵ are halogen atoms, and r is an integer of 0 to 8. .

[0035]

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In the general formula (10), X ^{9 to} X ¹¹ represent a halogen atom, X ^{12 to} X ¹⁶ are a halogen atom or a hydrogen atom, and s is an integer of 0 to 8.

[0037]

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In the general formula (11), X ^{17 to} X ²⁰ represent a halogen atom, X ^{21 to} X ²⁴ are a halogen atom or a hydrogen atom, and w is an integer of 0 to 8. As the halogen in the halogen-containing compound (2), chlorine or bromine,
Among them, it is preferable to use chlorine in view of activity, selectivity of a target product and the like. Further, r, s and w in the general formulas (9) to (11) are each preferably 0 to 3. Specific examples of the linear halogenated hydrocarbon represented by the general formulas (9) to (11) include 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,1
2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1,1,1-trichloropropane,
1,1,2,2-tetrachloropropane, 1,1,1-
Trichlorobutane, 1,1,2,2-tetrachlorobutane, 1,1,1-trichloropentane, 1,1,2,2
-Tetrachloropentane, 1,1,1-tribromoethane, 1,1,2,2-tetrabromoethane and the like. Among these, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane and hexachloroethane are particularly preferred.

The use of the halogen-containing compound (2) has the advantage that not only the catalytic activity and the selectivity of the trimer are remarkably improved, but also the deterioration of the catalyst with time can be improved. Further, the halogen-containing compound (3) is a halogenated cyclic hydrocarbon. As the cyclic hydrocarbon, a cyclic saturated hydrocarbon is preferable. As the halogen-containing compound (3), a cyclic saturated hydrocarbon substituted with three halogen atoms is particularly preferred. And, as the halogen atom, chlorine or bromine,
Among them, it is preferable to use chlorine in view of activity, selectivity of a target product and the like.

Specific examples of the halogen-containing compound (3) include 1,2,3-trichlorocyclopropane, 1,1,1
Trihalogenated cyclopropanes such as 2-trichlorocyclopropane, 1,2,3-tribromocyclopropane and 1,1,2-tribromocyclopropane;
Tetrahalogenation such as 3-tetrachlorocyclopropane, 1,1,2,2-tetrachlorocyclopropane, 1,1,2,3-tetrabromocyclopropane, 1,1,2,2-tetrabromocyclopropane Pentahalogenated cyclopropanes such as cyclopropane, pentachlorocyclopropane and pentabromocyclopropane; hexahalogenated cyclopropanes such as hexachlorocyclopropane and hexabromocyclopropane; 1,2,3-trichlorocyclobutane; -Trichlorocyclobutane,
Trihalogenated cyclobutane such as 1,2,3-tribromocyclobutane, 1,1,2-tribromocyclobutane, 1,2,3,4-tetrachlorocyclobutane, 1,
1,2,3-tetrachlorocyclobutane, 1,2,3
Tetrahalogenated cyclobutane such as 4-tetrabromocyclobutane, 1,1,2,3-tetrabromocyclobutane, 1,1,2,3,4-pentachlorocyclobutane,
1,1,2,2,3-pentachlorocyclobutane, 1,
1,2,3,4-pentabromocyclobutane, 1,1,
Pentahalogenated cyclobutane such as 2,2,3-pentabromocyclobutane, 1,1,2,2,3,4-hexachlorocyclobutane, 1,1,2,2,3,3-hexachlorocyclobutane, 1,1,1 Hexahalogenated cyclobutane such as 2,2,3,4-hexabromocyclobutane, 1,1,2,2,3,3-hexabromocyclobutane, heptahalogenated cyclobutane such as heptachlorocyclobutane, heptabromocyclobutane, octachloro Octahalogenated cyclobutane such as cyclobutane and octabromocyclobutane are exemplified.

Also, 1,2,3-trichlorocyclopentane, 1,1,2-trichlorocyclopentane, 1,1,2
Trihalogenated cyclopentane such as 2,3-tribromocyclopentane, 1,1,2-tribromocyclopentane, 1,2,3,4-tetrachlorocyclopentane,
1,1,2,3-tetrachlorocyclopentane, 1,
2,3,4-tetrabromocyclopentane, 1,1,
Tetrahalogenated cyclopentane such as 2,3-tetrabromocyclopentane, 1,2,3,4,5-pentachlorocyclopentane, 1,1,2,3,4-pentachlorocyclopentane, 1,1,1 2,2,3-pentachlorocyclopentane, 1,2,3,4,5-pentabromocyclopentane, 1,1,2,3,4-pentabromocyclopentane, 1,1,2,2,3 Pentahalogenated cyclopentanes such as -pentabromocyclopentane, 1,1,
2,3,4,5-hexachlorocyclopentane, 1,
Hexahalogenated cyclopentanes such as 1,2,3,4,5-hexabromocyclopentane, 1,1,2,2
3,4,5-heptachlorocyclopentane, 1,1,
Heptahalogenated cyclopentane such as 2,2,3,4,5-heptabromocyclopentane, 1,1,2,2
3,3,4,5-octachlorocyclopentane, 1,
Octahalogenated cyclopentanes such as 1,2,2,3,3,4,5-octabromocyclopentane; nonahalogenated cyclopentanes such as nonachlorocyclopentane; decahalogenated cyclopentanes such as decachlorocyclopentane; No.

Further, 1,2,3-trichlorocyclohexane, 1,1,2-trichlorocyclohexane, 1,1,
Trihalogenated cyclohexane such as 2,3-tribromocyclohexane and 1,1,2-tribromocyclohexane, 1,2,3,4-tetrachlorocyclohexane,
1,1,2,3-tetrachlorocyclohexane, 1,
2,3,4-tetrabromocyclohexane, 1,1,
Tetrahalogenated cyclohexane such as 2,3-tetrabromocyclohexane, 1,2,3,4,5-pentachlorocyclohexane, 1,1,2,3,4-pentachlorocyclohexane, 1,1,2,2 Penta such as 3-pentachlorocyclohexane, 1,2,3,4,5-pentabromocyclohexane, 1,1,2,3,4-pentabromocyclohexane, 1,1,2,2,3-pentabromocyclohexane Halogenated cyclohexane, 1,2,2
3,4,5,6-hexachlorocyclohexane, 1,
Hexahalogenated cyclohexane such as 2,3,4,5,6-hexabromocyclohexane, 1,1,2,3
4,5,6-heptachlorocyclohexane, 1,1,
Heptahalogenated cyclohexane such as 2,3,4,5,6-heptabromocyclohexane, 1,1,2,2
3,4,5,6-octachlorocyclohexane, 1,
Octahalogenated cyclohexane such as 1,2,2,3,4,5,6-octabromocyclohexane,
Nona halogenated cyclohexane such as 2,2,3,3,4,5,6-nonachlorocyclohexane, 1,1,2,2
Examples include decahalogenated cyclohexane such as 2,3,3,4,4,5,6-decachlorocyclohexane, undecahalogenated cyclohexane such as undecachlorocyclohexane, and dodecahalogenated cyclohexane such as dodecachlorocyclohexane.

Among the above, especially 1,2,3-trichlorocyclopropane, pentachlorocyclopropane,
2,3,4-tetrachlorocyclobutane, 1,2,3
4,5-pentachlorocyclopentane, 1,2,3
4,5,6-Hexachlorocyclohexane is preferred. The use of the halogen-containing compound (3) has an advantage that not only the catalytic activity and the selectivity of the trimer are remarkably improved, but also the deterioration of the catalyst with time can be improved. The halogen-containing compound (4) is an allyl halide compound represented by the following general formula (12).

[0044]

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In the general formula (12), R ^{11 to} R ¹⁴ represent a hydrogen atom or an alkyl group, X ²⁵ represents a hydrogen atom, an alkyl group or a halogen atom, and X ²⁶ represents a halogen atom. It is preferable to use chlorine or bromine as the halogen, especially chlorine in view of activity, selectivity of the target product, and the like. Specific examples of the halogen-containing compound (4) include allyl chloride, 3,3-dichloro-1-propene,
-Chloro-1-butene, 3,3-dichloro-1-butene, 1-chloro-2-butene, 1,1-dichloro-2-
Butene, 3-chloro-3-methyl-1-butene, 3-chloro-1-pentene, 3,3-dichloro-1-pentene, 4-chloro-2-pentene, 4,4-dichloro-2
-Pentene, 1-chloro-2-pentene, 1,1-dichloro-2-pentene and the like, with allyl chloride being most preferred.

The use of the halogen-containing compound (4) not only significantly improves the catalytic activity and the selectivity of the trimer, but also
Since the activity per halogen atom is high, the amount of the halogen-containing compound to be used is small, and the amount of the halogen-containing decomposition product generated in the reaction step or distillation purification is small, so that the obtained trimer is purified. This has the advantage that the halogen-containing impurities can be easily separated and the target product can be recovered with high purity. In the present invention, t-butyldimethylsilyl triflate (t-BuMe ₂ SiOSO ₂ C) is used as the halogen-containing compound.
F ₃ ), tris (pentafluorophenyl) boron (B
(C ₆ F ₅ ) ₃ ), trifluoromethanesulfonic acid (C
F ₃ SO ₃ H), hexafluoroisopropanol ((CF ₃ ) ₂ CHOH) and the like can also be suitably used.

In the present invention, an α-olefin is used in a liquid reaction medium by using a chromium-based catalyst formed from each of the above catalyst components (a) to (c), preferably (a) to (d). Of low polymerization. And a chromium compound (a)
When a chromium compound containing a halogen such as chromic chloride is used, the chromium compound also functions as the halogen-containing compound (d). Similarly, when an alkylaluminum compound containing a halogen such as diethylaluminum monochloride is used as the alkylaluminum compound (c), the alkylaluminum compound also functions as a halogen-containing compound (d).

In the present invention, the raw material α used for the low polymerization reaction
As the olefin, a substituted or unsubstituted α-olefin having 2 to 10 carbon atoms is used. Specifically, ethylene, propylene, 1-butene, 1-hexene, 1-
Octene, 3-methyl-1-butene, 4-methyl-1-
Penten and the like. In particular, ethylene is suitable as the raw material α-olefin, and according to the present invention, 1-hexene, a trimer thereof, can be obtained from ethylene with high yield and high selectivity.

In the present invention, as a reaction solvent, butane, pentane, 3-methylpentane, hexane, heptane, 2-methylhexane, octane, cyclohexane,
A chain or alicyclic saturated hydrocarbon having 4 to 20 carbon atoms such as methylcyclohexane and decalin, and an aromatic hydrocarbon such as benzene, toluene, xylene, ethylbenzene, mesitylene and tetralin are used. These can be used alone or as a mixed solvent. In the present invention, the α-olefin itself as a reaction raw material or another olefin may be used as a solvent. When an olefin is used as the solvent, it is preferable to use a liquid at room temperature. Particularly preferred as the solvent is a chain saturated hydrocarbon or an alicyclic saturated hydrocarbon having 4 to 7 carbon atoms. By using these solvents, by-products of the polymer can be suppressed, and when an alicyclic saturated hydrocarbon is used, there is an advantage that a high catalytic activity can be obtained.

The low-polymerization reaction of the α-olefin according to the method of the present invention is preferably carried out using a continuous reactor, for example, a stirred type flow reactor, particularly a stirred tank type flow reactor. The present invention relates to the supply of a chromium-based catalyst to the reaction zone at the start of the reaction when the continuous low-polymerization reaction of α-olefin is performed using the above-mentioned catalyst and the above-mentioned reactor, particularly a stirred tank type flow reactor. Is performed under specific conditions.

That is, the present invention relates to a method for preparing a chromium compound (a) in the reaction zone at the start of the reaction, in which the nitrogen-containing compound (b), the alkylaluminum compound (c), and the halogen-containing compound (d), if present, are used. It is characterized in that the low polymerization reaction is started by supplying each component of the chromium-based catalyst and an α-olefin so that the ratio becomes larger than the molar ratio in the steady state. Here, when the reaction starts,
Chromium compound (a) and nitrogen-containing compound (b), alkylaluminum compound (c) and halogen-containing compound (d)
Refers to the point in time when the low-polymerization reaction starts for the first time.

In the present invention, by supplying each component of the chromium-based catalyst into the reaction zone under the above specific conditions,
In the early stage of the reaction, the activity of the chromium-based catalyst can be significantly improved, and the amount of by-produced polymer can be significantly reduced. Although the reason for this is not sufficiently clear, the molar ratio of each component of the nitrogen-containing compound (b), the alkylaluminum compound (c) and, if present, the halogen-containing compound (d) to the chromium compound (a) at the start of the reaction is determined. If each component of the chromium-based catalyst is supplied so as to be larger than the molar ratio in the steady state, it may be possible to efficiently form catalytically active species effective for the low polymerization reaction of α-olefin. Presumed. In the present invention, it is preferable to continuously supply the chromium-based catalyst and the α-olefin to the reaction zone while maintaining a specific contact mode.

The above-mentioned specific contact mode means that when a chromium-based catalyst and an α-olefin are continuously supplied to a reaction zone to initiate a low polymerization reaction, a chromium compound (a) supplied to the reaction zone and an alkyl An aspect in which the aluminum compound (c) does not come into contact with the aluminum compound (c) in advance is maintained. That is, each of the chromium compound (a) and the alkylaluminum compound (c) may be brought into contact with the nitrogen-containing compound (b) or the halogen-containing compound (d) selected from amines, amides and imides in advance. It is preferred that the two be contacted for the first time in the presence of the α-olefin in the reaction zone. When the catalyst is formed in this way, the catalytic activity is significantly improved, and the selectivity of the trimer is very high,
Further, there is an advantage that the purity of the obtained α-olefin low polymer is extremely high.

The method for forming a catalyst according to the present invention will be described in more detail. The catalyst is prepared by directly supplying the components (a) to (c), preferably (d), directly to the reaction zone at a temperature of usually from 20 to 150 ° C, preferably from 50 to 100 ° C. Is generated. The supply of the catalyst component is performed in such a manner that the chromium compound (a) and the alkylaluminum compound (c) contact for the first time in the presence of the α-olefin as described above. The reason that a high-performance catalyst is produced by this embodiment is that the reactant produced by contact between the chromium compound (a) and the alkylaluminum compound (c) is extremely unstable and easily decomposes as it is. It is considered that the presence of the α-olefin causes coordination of the α-olefin with the α-olefin, and the reaction product is appropriately stabilized.

The concentration of the chromium compound (a) in the reaction zone at the start of the reaction is preferably 2 × 10 ⁻² mmol or less, more preferably 5 × 10 ⁻⁷ to 1 × 10 per liter of the reaction medium. in the range ^-2 mmol, also, the molar ratio of each component in the reaction zone is preferably (a) :( b) :( c ) = 1: 150 or more: 1500 or more, more preferably 1: 150 ~ 1000: 1500
5000, particularly preferably 1: 200 to 500: 200
The range is from 0 to 3000. When the halogen-containing compound (d) is used, preferably (a):
(B) :( c) :( d) = 1: 150 or more: 1500 or more: 150 or more, more preferably 1: 150 to 100
0: 1500 to 5000: 150 to 1000, particularly preferably 1: 200 to 500: 200 to 3000: 200
５００500.

If the ratio of each of the above components is too low, the catalyst activity tends to be low in the initial stage of the reaction and the by-product of the polymer tends to increase. By adjusting the ratio of each of the above components within the above range, the catalyst activity can be remarkably improved in the initial stage of the reaction, a low polymerization reaction can be performed while maintaining high activity, and the amount of by-produced polymer is significantly reduced. It is preferable because it can be reduced. Although the reason for this is not clear, if the ratio of each of the above components is too low, a catalytically active species that is effective for a low polymerization reaction cannot be formed, and conversely, an active species that is effective for forming a by-product polymer is formed. If the ratio is within the above range, it is presumed that a catalytically active species effective for the low polymerization reaction can be formed very easily.

At the start of the above reaction, the molar ratio of nitrogen-containing compound (b) / chromium compound (a), the molar ratio of alkylaluminum compound (c) / chromium compound (a) and the halogen-containing compound (d) / chromium compound As a method of supplying each component of the chromium-based catalyst and the α-olefin so that the molar ratio of (a) becomes larger than the molar ratio in the steady state, for example, the olefin and each component are supplied to a stirred tank reactor. A method of simultaneously supplying and adjusting the method or a method of previously supplying at least the alkyl aluminum compound of the component (c) and the α-olefin to the reactor and then supplying the chromium compound of the component (a) to the reactor. And the like.

In the former method, the molar ratio of each of the components (b) to (d) with respect to the chromium compound (a) in the reaction zone is maintained for a certain period of time from the start of the reaction such that the molar ratio becomes larger than in the steady state. After the catalytic activity (efficiency) of the chromium-based catalyst has been sufficiently improved, the reaction is continued by gradually decreasing the supply amounts of the components (b) to (d) to a steady-state molar ratio to continue the reaction. The low polymerization reaction of olefin can be carried out industrially advantageously.

In the latter method, at least the alkylaluminum compound of component (c) and α
An olefin is supplied in advance, and a predetermined amount of the chromium compound of the component (a), the other components (b) to (d), and the α-olefin are supplied thereto, whereby the (b) relative to the component (a) is supplied. The reaction is continued by gradually reducing the molar ratio of the components (1) to (d) from a large value to a molar ratio in a steady state, whereby the low polymerization reaction of α-olefin can be carried out industrially advantageously.

In the latter method, the concentration of the alkylaluminum compound (c) previously supplied to the reaction zone before the initiation of the low polymerization reaction is 5 ppm or more, preferably 10 ppm or more, more preferably 10 to 10 ppm. 50 ppm
Range. If the concentration of the alkylaluminum compound (c) in the reaction zone is too low at the time of starting the reaction by continuously supplying the chromium-based catalyst and the α-olefin, the catalyst activity is low in the initial stage of the reaction, In addition, polymer by-products tend to increase.

The following method is mentioned as a specific embodiment of the latter method. (1) An α-olefin, a nitrogen-containing compound (b), an alkylaluminum compound (c) and a halogen-containing compound (d) are previously supplied into a reaction zone, and a chromium compound (a) and an α-olefin are added thereto. And (b) ~
Component (d) is a fixed amount (steady amount) so as to have the above molar ratio.
A method of supplying and initiating a reaction. (2) An α-olefin and an alkylaluminum compound (c) are supplied in advance to a reaction zone, and a chromium compound (a), an alkylaluminum compound (c) and an α-olefin are supplied in fixed amounts (steady amounts). And the nitrogen-containing compound (b) and the halogen-containing compound (d) are supplied in excessive amounts, respectively, and the reaction is started so that each of the components has the above molar ratio. When the activity of the chromium-based catalyst is sufficiently improved, A method in which the components (b) and (d) are reduced to a certain amount (steady amount) to continue the reaction.

(3) An α-olefin, an alkylaluminum compound (c) and a halogen-containing compound (d) are previously supplied to the reaction zone, and the chromium compound (a), the alkylaluminum compound (c), A constant amount (constant amount) of the compound (d) and the α-olefin, and an excess amount of the nitrogen-containing compound (b) are supplied, respectively, and the reaction is started so that the respective components have the above molar ratios. A method in which the reaction is continued by reducing the nitrogen-containing compound (b) to a certain amount (steady amount) when the activity of the catalyst is sufficiently improved. (4) An α-olefin, a nitrogen-containing compound (b) and an alkylaluminum compound (c) are previously supplied into a reaction zone, and a chromium compound (a) is added thereto in a fixed amount (steady amount), and a halogen-containing compound is supplied. An excessive amount of (d) is supplied, and the reaction is started so that each component has the above molar ratio. When the activity of the chromium-based catalyst is sufficiently improved, the component (d) is reduced to a certain amount (steady amount). A method of reducing and continuing the reaction.

According to each of the above methods, after the reaction is started, the catalytic activity of the chromium-based catalyst is sufficiently improved.
The reaction can be continued by reducing the component (d) to a steady state supply amount, and the molar ratio of each component in the reaction zone in the steady state is preferably (a) :( b) :( c) = 1:
0.1 to 100: 0.1 to 500, more preferably 1:
1 to 10: 5 to 50. When the halogen-containing compound (d) is used, preferably, (a):
(B): (c): (d) = 1: 0.1 to 100: 0.1
To 500: 0.1 to 100, more preferably 1 to 1 to 1
The range is from 0: 5 to 50: 1 to 10. However, the concentration of the chromium compound as component (a) is preferably
A low concentration region of 2 × 10 ⁻² mmol or less per liter, more preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻² mmol,
By using the chromium compound (a) in such a low concentration region, the catalyst efficiency can be improved and the catalyst cost can be reduced.

The low polymerization reaction of the α-olefin according to the present invention is usually carried out at 20 to 150 ° C. and at 10 to 200 kg / cm.
It is performed under the conditions of ² . Suitable reaction temperatures and pressures are 50-100 ° C. and 20-100 kg /
cm ² . When hydrogen is present in the reaction zone,
In general, effects such as improvement in catalytic activity and trimer selectivity and reduction in adhesion of a polymer to a reactor wall or the like are obtained. Hydrogen is preferably present in the gas phase in an amount of 0.1 to 15% by volume. The α-olefin low polymer can be recovered from the reaction product by a conventional method. Usually, if a by-product polymer is present, it is first separated and then distilled to separate the α-olefin low polymer.
to recover.

[0065]

The present invention will be described in more detail with reference to the following examples.
As will be explained, the present invention is limited to these Examples.
There is no. Example 1 A vessel having two catalyst supply pipes and one reaction liquid discharge pipe
2 liters of autoclave in 150 ℃ dryer
After drying and assembling, the atmosphere was replaced with vacuum nitrogen. This auto
Ethylene and 2,5-dimethylpyro
, Triethylaluminum and hexachloroethane
Was charged. That is, 1 n-heptane is added to the autoclave.
Then, at 80 ° C., 35 kg /
cm ^TwoG, and then add 2,5-dimethyl
Tyl pyrrole, triethyl aluminum, hexachloro
0.96 mmol, 9.6 mmol of ethane respectively
0.96 mmol was charged.

Into this autoclave, 2,5-dimethylpyrrole was added at 0.036 mmol /
hr, 0.24 mmol / h of triethylaluminum
r, and 0.024 mmol / hr of hexachloroethane
At a supply rate of, and each was continuously supplied as an n-heptane solution. From the other catalyst supply pipe, chromium (III) -2-ethylhexanoate Cr (2EH
A) ₃ a 0.006mmol / hr (3.0mg / h
It was continuously supplied as an n-heptane solution at a supply rate of r). The total supply of n-heptane to the autoclave is 1
Liter / hr. The autoclave was maintained at 80 ° C., and ethylene was continuously supplied so that the total pressure became 35 kg / cm ² G, thereby causing a low polymerization reaction of ethylene. The reaction solution was withdrawn from the autoclave via a reaction solution withdrawal tube so that the content liquid was 1 liter. The extracted reaction solution was introduced into a degassing tank, degassed to normal pressure, and the liquid component and the gas component were analyzed by gas chromatography. Table 1 shows the results obtained by measuring the catalyst efficiency and the amount of by-produced polyethylene at regular intervals and the molar ratio of each component to chromium.

Comparative Example 1 A low polymerization reaction was carried out in the same manner as in Example 1 except that ethylene, 2,5-dimethylpyrrole, triethylaluminum and hexachloroethane were not previously charged in the autoclave. Table 1 shows the results.
1 to 4 show the time dependence of the concentration of each catalyst component. 1 to 4, TEA represents triethylaluminum, DMP represents 2,5-dimethylpyrrole, and HCE represents hexachloroethane.

[0068]

[Table 1]

[0069]

Industrial Applicability According to the present invention, a low yield of α-olefins can be obtained by suppressing the by-product of a polymer at a high yield and a high selectivity without an induction period for activating a catalyst at the beginning of a low polymerization reaction. The polymer can be produced industrially advantageously.

[Brief description of the drawings]

FIG. 1 is a diagram showing the time dependence of the concentration of Cr (2EHA) _{3 in} a reactor.

FIG. 2 is a diagram showing the time dependence of the concentration of TEA in a reactor.

FIG. 3 is a diagram showing the time dependence of the concentration of DMP in a reactor.

FIG. 4 is a diagram showing the time dependence of the concentration of HCE in a reactor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Okano 3-10, Ushidori, Kurashiki-shi, Okayama Prefecture Mitsubishi Chemical Mizushima Development Laboratory Co., Ltd.

Claims (15)

[Claims] 1. An α-olefin using a chromium-based catalyst comprising at least a combination of a chromium compound (a), a nitrogen-containing compound (b) selected from the group consisting of amines, amides and imides and an alkylaluminum compound (c). In the continuous production of an α-olefin low polymer by low polymerization reaction of the compound (a), the molar ratio of the nitrogen-containing compound (b) / chromium compound (a) in the reaction zone at the start of the reaction and the alkylaluminum compound (C)
Wherein each component of the chromium-based catalyst and the α-olefin are supplied so as to initiate the low polymerization reaction of the α-olefin so that the molar ratio of the chromium compound (a) becomes larger than the molar ratio in the steady state. A method for producing an α-olefin low polymer. 2. A chromium compound (a) to be supplied to a reaction zone.
2. The α-olefin low polymer according to claim 1, wherein each component of the chromium-based catalyst and the α-olefin are continuously supplied to the reaction zone while maintaining a state in which the α-olefin and the alkylaluminum compound (c) do not come into contact in advance. Production method. 3. The molar ratio of the nitrogen-containing compound (b) and the alkylaluminum compound (c) to the chromium compound (a) in the reaction zone after the start of the reaction is gradually increased from a large value to a value in a steady state. The method for producing an α-olefin low polymer according to claim 1 or 2, wherein the supply of each component of the chromium-based catalyst is adjusted so as to decrease the amount. 4. The reaction zone before reaction is started
-An olefin and an alkylaluminum compound (c) are supplied, and then each component of the chromium-based catalyst and α-
An olefin is continuously supplied to the reaction zone.
The method for producing an α-olefin low polymer according to any one of the above. 5. The concentration of the alkylaluminum compound (c) previously supplied to the reaction zone before the start of the reaction is 5 pp.
The method for producing an α-olefin low polymer according to claim 4, which is at least m. 6. The concentration of the chromium compound (a) in the reaction zone at the start of the reaction is 2.
6. The composition according to claim 1, wherein 0 × 10 ⁻² mmol or less, and the molar ratio of the components (a) to (c) is (a) :( b) :( c) = 1: 150 or more and 1500 or more. The method for producing an α-olefin low polymer according to any one of the above. 7. In a steady state after the start of the reaction, the concentration of the chromium compound (a) in the reaction zone is 2.0 × 10 ⁻² mmol or less per liter of the reaction medium, and (a) to (c). )) The molar ratio of the components is (a) :( b):
The method for producing an α-olefin low polymer according to any one of claims 1 to 6, wherein (c) = 1: 0.1 to 100: 0.1 to 500. 8. The chromium-based catalyst comprises a combination of a chromium compound (a), a nitrogen-containing compound (b) selected from the group consisting of amines, amides and imides, an alkylaluminum compound (c) and a halogen-containing compound (d). A method for producing an α-olefin low polymer according to any one of claims 1 to 5. 9. The components of the chromium-based catalyst and α-chromium compound such that the molar ratio of the halogen-containing compound (d) / chromium compound (a) in the reaction zone at the start of the reaction is higher than the molar ratio in the steady state. 9. An olefin is supplied.
The method for producing an α-olefin low polymer according to the above. 10. The molar ratio of the nitrogen-containing compound (b), alkylaluminum compound (c) and halogen-containing compound (d) to the chromium compound (a) in the reaction zone after the start of the reaction is changed from a large value to a steady state. The method for producing an α-olefin low polymer according to claim 8 or 9, wherein the supply of each component of the chromium-based catalyst is adjusted so as to gradually decrease to a value. 11. The concentration of the chromium compound (a) in the reaction zone at the start of the reaction is 2.0 × 10 ⁻² mmol or less per liter of the reaction medium, and (a) to (c).
The molar ratio of the component (d) is (a) :( b) :( c) :( d)
= 1: 150 or more: 1500 or more: 150 or more. The process for producing an α-olefin low polymer according to any one of claims 8 to 10. 12. In a steady state after the start of the reaction, the concentration of the chromium compound (a) in the reaction zone is 2.0 × 10 ⁻² mmol or less per liter of the reaction medium, and (a) to (d). The molar ratio of the components is (a) :( b):
(C): (d) = 1: 0.1-100: 0.1-50
The method for producing an α-olefin low polymer according to any one of claims 8 to 11, wherein 0: 0.1 to 100. 13. The halogen-containing compound (d) is selected from the group consisting of IIIA, IIIB, IVA, IVB, VA, VB and VI of the periodic table.
The method for producing an α-olefin low polymer according to any one of claims 8 to 12, comprising an element selected from the group consisting of Group B. 14. The method for producing an α-olefin low polymer according to claim 1, wherein the low polymerization reaction of the α-olefin is performed using a stirred type flow reactor. 15. The α-olefin is ethylene;
The method for producing an α-olefin low polymer according to any one of claims 1 to 14, wherein the low olefin polymer is mainly 1-hexene.